unsigned long p = 0;
unsigned long t = 0;
int l = 0;
int s = 0;

void setup()
{
    pinMode(13, OUTPUT);
}

void loop()
{
 if (s == 1) {
  if(millis()-p > 200) {
   p = p + 200;
   l = !l;
  }
 }
 digitalWrite(13, l);

 if (digitalRead(2) == LOW) {
  t = millis();
  delay(20);
  while (digitalRead(2) == LOW) {
   delay(5);
  }
  if (millis()-t < 500) {
    s=0;
    l=1;
    for (int i=0; i<20; i=i+1) {
     if (digitalRead(2)==LOW) {
      s=1;
      delay(20);
      while(digitalRead(2)==LOW) {
       delay(5);
      }
      p=millis();
      break;
     }
     delay(10);
    }
   } else {
    s=0;
    l=0;
   }
 }
}